3 Connect to Xfce

4 Connect to Mate Desktop

5 Connect to KDE Plasma

5.1 Fedora 24

Run startkde in ${HOME}/.Xclients.

$ echo "startkde" > ~/.Xclients
$ chmod a+x ~/.Xclients

5.2 CentOS 7

Run startkde in ${HOME}/.Xclients.

$ echo "startkde" > ~/.Xclients
$ chmod a+x ~/.Xclients

KDE Plasma in CentOS 7 does not respect Xvnc geometry, the resolution of XRDP session will be the largest one. For avoid this issue, run "xrandr -x <width>x<height>".
A setting of "xrandr -x <width>x<height>" is saved after rebooting machine.